tty: Make tiocgicount a handler

commit d281da7ff6f70efca0553c288bb883e8605b3862 upstream.

Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.

This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index bc4f45de6f88d2ec7517147d266cb5891d6b6138..9584289fe59802501debf8992f530455391f6528 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -96,6 +96,7 @@
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/seq_file.h>
+#include <linux/serial.h>
 
 #include <linux/uaccess.h>
 #include <asm/system.h>
@@ -2457,6 +2458,20 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
        return tty->ops->tiocmset(tty, file, set, clear);
 }
 
+static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
+{
+       int retval = -EINVAL;
+       struct serial_icounter_struct icount;
+       memset(&icount, 0, sizeof(icount));
+       if (tty->ops->get_icount)
+               retval = tty->ops->get_icount(tty, &icount);
+       if (retval != 0)
+               return retval;
+       if (copy_to_user(arg, &icount, sizeof(icount)))
+               return -EFAULT;
+       return 0;
+}
+
 struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
 {
        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
@@ -2577,6 +2592,12 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        case TIOCMBIC:
        case TIOCMBIS:
                return tty_tiocmset(tty, file, cmd, p);
+       case TIOCGICOUNT:
+               retval = tty_tiocgicount(tty, p);
+               /* For the moment allow fall through to the old method */
+               if (retval != -EINVAL)
+                       return retval;
+               break;
        case TCFLSH:
                switch (arg) {
                case TCIFLUSH:

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 7f28307095121766d685350dad865e72f7d312c2..232e2bbb97b999c05cede83132e38f23dd970b57 100644 (file)
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1074,10 +1074,10 @@ uart_wait_modem_status(struct uart_state *state, unsigned long arg)
  * NB: both 1->0 and 0->1 transitions are counted except for
  *     RI where only 0->1 is counted.
  */
-static int uart_get_count(struct uart_state *state,
-                         struct serial_icounter_struct __user *icnt)
+static int uart_get_icount(struct tty_struct *tty,
+                         struct serial_icounter_struct *icount)
 {
-       struct serial_icounter_struct icount;
+       struct uart_state *state = tty->driver_data;
        struct uart_icount cnow;
        struct uart_port *uport = state->uart_port;
 
@@ -1085,19 +1085,19 @@ static int uart_get_count(struct uart_state *state,
        memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
        spin_unlock_irq(&uport->lock);
 
-       icount.cts         = cnow.cts;
-       icount.dsr         = cnow.dsr;
-       icount.rng         = cnow.rng;
-       icount.dcd         = cnow.dcd;
-       icount.rx          = cnow.rx;
-       icount.tx          = cnow.tx;
-       icount.frame       = cnow.frame;
-       icount.overrun     = cnow.overrun;
-       icount.parity      = cnow.parity;
-       icount.brk         = cnow.brk;
-       icount.buf_overrun = cnow.buf_overrun;
+       icount->cts         = cnow.cts;
+       icount->dsr         = cnow.dsr;
+       icount->rng         = cnow.rng;
+       icount->dcd         = cnow.dcd;
+       icount->rx          = cnow.rx;
+       icount->tx          = cnow.tx;
+       icount->frame       = cnow.frame;
+       icount->overrun     = cnow.overrun;
+       icount->parity      = cnow.parity;
+       icount->brk         = cnow.brk;
+       icount->buf_overrun = cnow.buf_overrun;
 
-       return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
+       return 0;
 }
 
 /*
@@ -1150,10 +1150,6 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
        case TIOCMIWAIT:
                ret = uart_wait_modem_status(state, arg);
                break;
-
-       case TIOCGICOUNT:
-               ret = uart_get_count(state, uarg);
-               break;
        }
 
        if (ret != -ENOIOCTLCMD)
@@ -2305,6 +2301,7 @@ static const struct tty_operations uart_ops = {
 #endif
        .tiocmget       = uart_tiocmget,
        .tiocmset       = uart_tiocmset,
+       .get_icount     = uart_get_icount,
 #ifdef CONFIG_CONSOLE_POLL
        .poll_init      = uart_poll_init,
        .poll_get_char  = uart_poll_get_char,

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 3873660d821776cab0d2950633cd17169b728643..b40884a4191d49790a6aa2471f4478ec83b06124 100644 (file)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -519,6 +519,18 @@ static int serial_tiocmset(struct tty_struct *tty, struct file *file,
        return -EINVAL;
 }
 
+static int serial_get_icount(struct tty_struct *tty,
+                               struct serial_icounter_struct *icount)
+{
+       struct usb_serial_port *port = tty->driver_data;
+
+       dbg("%s - port %d", __func__, port->number);
+
+       if (port->serial->type->get_icount)
+               return port->serial->type->get_icount(tty, icount);
+       return -EINVAL;
+}
+
 /*
  * We would be calling tty_wakeup here, but unfortunately some line
  * disciplines have an annoying habit of calling tty->write from
@@ -1171,6 +1183,7 @@ static const struct tty_operations serial_ops = {
        .chars_in_buffer =      serial_chars_in_buffer,
        .tiocmget =             serial_tiocmget,
        .tiocmset =             serial_tiocmset,
+       .get_icount =           serial_get_icount,
        .cleanup =              serial_cleanup,
        .install =              serial_install,
        .proc_fops =            &serial_proc_fops,

diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index b086779825252b40612062391dad9c67c3912ddf..db2d227694da664f2e789767927da0126de7c64d 100644 (file)
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -224,6 +224,12 @@
  *     unless the tty also has a valid tty->termiox pointer.
  *
  *     Optional: Called under the termios lock
+ *
+ * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount);
+ *
+ *     Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
+ *     structure to complete. This method is optional and will only be called
+ *     if provided (otherwise EINVAL will be returned).
  */
 
 #include <linux/fs.h>
@@ -232,6 +238,7 @@
 
 struct tty_struct;
 struct tty_driver;
+struct serial_icounter_struct;
 
 struct tty_operations {
        struct tty_struct * (*lookup)(struct tty_driver *driver,
@@ -268,6 +275,8 @@ struct tty_operations {
                        unsigned int set, unsigned int clear);
        int (*resize)(struct tty_struct *tty, struct winsize *ws);
        int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
+       int (*get_icount)(struct tty_struct *tty,
+                               struct serial_icounter_struct *icount);
 #ifdef CONFIG_CONSOLE_POLL
        int (*poll_init)(struct tty_driver *driver, int line, char *options);
        int (*poll_get_char)(struct tty_driver *driver, int line);

diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 453ab9517edd9fa5744c10979dce31808f8e5a60..71d491fab629c647b3c921a4557a7f85000eaa9f 100644 (file)
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -257,6 +257,8 @@ struct usb_serial_driver {
        int  (*tiocmget)(struct tty_struct *tty, struct file *file);
        int  (*tiocmset)(struct tty_struct *tty, struct file *file,
                         unsigned int set, unsigned int clear);
+       int  (*get_icount)(struct tty_struct *tty,
+                       struct serial_icounter_struct *icount);
        /* Called by the tty layer for port level work. There may or may not
           be an attached tty at this point */
        void (*dtr_rts)(struct usb_serial_port *port, int on);